Construction jack



Feb, 5 1924., 1,483,004

J. W. M DOW v CONSTRUCTI ON JACK Fe. 5 1924. v 1,483,004

J. W. M DQW CONSTRUCTION-TACK Filed May 15. 1922 v '2 Sheets-Sheet 2 0 ii W 'i I ill) Patented Feb. 5, 1924.

am rait JOHN W. MAODOW, OF NEWARK, NEW JERSEY.

cons'rnoorion JACK.

Application filed May 15,

To aZZao/zom it may concern:

Be it known that I, JOHN W. MACDOW, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented a new and useful Construction Jack, of which the followmg is a specification.

This invention relates to construction jacks for use in erecting buildings and for other purposes.

The object of the invention is to provide a strong, adjustable jack of this character which may be used in supporting beams or other objects and after being located beneath the beam may be raised and adjusted to more accurately fit thereunder and to elevate said beam.

it-h the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed, may be made within the scope of what is claimed without departing from the spirit of the invention.

In the accompanying drawings Figure 1 represents a side elevation of a jack constructed in accordance with this invention.

Fig. 2 is a detail sectional view taken on the line 22 of Fig. 1.

Fig. 3 is a top plan view thereof.

Fig. 4 is a central vertical section thereof with the head shown broken ofl' for convenience in illustration.

Fig. 5 is a transverse section taken on the line 5-5 of Fig. 4, and

Fig. 6 is an end elevation of a head with the clamping jaw removed.

In the embodiment illustrated, a supporting base 1 is shown having a recess 1 in the bottom thereof communicating with a bore in which is mounted to turn a reduced extension 3 of a block 2 which carries an upstanding screw 4. This screw 4 has threaded engagement with a socket in the lower end of the body member 5 of the jack, so that when the block 2 is rotated by means of a jack bar 20, the body member 5 will be raised or lowered according to the direction in which block 2 is turned.

The upper portion of the body member 5 is made angular in cross section as shown 1922. Serial No. 561,070.

in Fig. ,5, and has mounted for vertical adjustment therein, the shank 7 of an object supporting head 10. This shank 7 and the opposed walls of the body 5 are equipped with registering apertures 9 and 9 to receive keys as 8 to hold shank 7 in adjusted relation to the member 5.

The article supporting member or head 10 comprises laterally spaced parallel angle bars 11 and 12 which are L-shaped in cross section as shown in Fig. 2, and are connected with the upper end of the shank 7 by plates 13 which are bolted or otherwise secured to said shank and to said bars as is shown clearly in Figs. 1 and 4.. These plates 13 will hold the bars in operative position fixedly mounted on the shank 7 and said bars form guides for clamping jaws 14c and 15 which are slidable between the bars projecting above and below them, as is shown clearly in Fig. 1. These jaws are constructed as shown in detail in Fig. 2,

being provided in their outer side faces with cut out portions or recesses 16 to receive the upright members of the angle bars 11 and 12 as shown in Fig. 2. Removable headed pins 18 are designed to be inserted through registering apertures 17 formed in the upright members of the angle bars 11 and 12 as shown in Fig. 1, and are designed to hold the clamps 14 and 15 engaged with the object to be supported, the pins being extended through apertures at the rear of said clamps as is shown clearly in Fig. 1.

In the use of this jack, the parts being in the position shown in Figs. 1 and 4 when it is desired to raise head 10 to position it under an object to be supported, the pins 8 are removed and the head lifted bodily until it is properly positioned when the pins 8 are inserted through registering apertures 9 and 9 in the members 5 and 7 which will hold the head connected with the body of the jack in position to support a beam or other object. If it is desired to raise the beam so supported, the block 2 is turned by means of the jack bar 20 which elevates the body member 5 which carries with it the head 10.

It is of courseunderstood that the extent of movement of the member 5 will be controlled by the size of the threads on the screw 4 and in the socket of member 5.

This jack is designed to be constructed entirely of metal, except possibly the jaws 14: and 15 which may be made of wood or metal or of metal lines or faces with some suitable material to prevent abrasion of an object to be clamped between them.

The construction of the jack with metal, will greatly prolong its life and strengthen it, adapting it to support heavy weights.

I claim:

1. A j ack of the class described comprising a vertically adjustable supporting member having laterally extending arms carried by its upper end, clamping jaws, said arms and aws having registering apertures and pins extending through said apertures to lock the jaws in adjusted position and hold them against possible slipping.

2. A jack of the class described comprising a supporting base, an object engaging head mounted thereon and composed of laterally spaced parallel angle bars, the upright flanges of which are equipped with a plurality of registering apertures, clamping jaws mounted to slide between said bars and recessed in their opposed faces to receive the upright members of the bars, the recessed portion of said jaws being apertured to register with the apertures in said bars, and pins to extend through the apertures in the bars and jaws for holding said jaws in adjusted position.

In testimony that I claim the foregoing as my own, I have hereto aiiixed my signature in the presence of two witnesses.

JOHN W. MAoDOW.

Witnesses:

WILLIAM D. GALLAGHER, WILLIAM HARVEY. 

